Electric switch



April 14, 1925. 1,533,251

H. H. JOHNSTON ELECTRIC SWITCH Filed June 5, 1922 Fig. I.

' Fig. 2.

WITNESSES: INVENTOR W Howard H. JohnsTon.

ATTORNEY Patented Apr. 14, 1925.

UNITED STATES HOWARD H. JOHNSTON, OF FOREST HILLS BORO, PENNSYLVANIA,ASSIGNOR TO WES'1' INGHO'USE ELECTRIC & MANUFACTURING COMPANY,

SYLVANIA.

PATENT OFFICE.

A CORPORATION OF PENN- ELECTRIC SWITCH.

Application filed June 5,

To all whom it may concern:

Be it known that I, HOWARD H. J OHNBTON, a citizen of the United States,and a resident of Forest Hills Boro in the county of Allegheny and Stateof lennsylvania, have invented a new and useful Improvement in ElectricSwitches, of which the following is a specification.

My invention relates to electric switches and particularly to means forextinguishing arcs that are formed across a pair of relatively movablecontact members.

- Relatively movable contact members of a circuit interrupter forcontrolling circuits of high voltage are usually provided with a pair ofarc horns and a blowout coil, for setting up a flux across the zonebetween the horns, to exercise a blow-out effect upon the arcs that areformed across the horns.

I My invention has for its object the provi sion of auxiliary blowoutmeans that accelerate the movement of the are when it reaches a point atsuch distance from the.

main blowoutcoil that the rate of movement of the arc tends to decrease.

Still another object of my invention is to provide a simple andeffective blowout device of greater efliciency than those heretoforeemployed.

As shown in the accompanying drawings,

Figure 1 is a view, partially in side elevation and partially insection, showing the manner in which my invention may be applied to anelectric switch, and

Fig. 2 is a diagrammatic view of a modified form thereof.

The apparatus comprises an arc chute 3 that may be of the usual form andwhich is provided with insulating barriers 4 and pole pieces 5 that aremounted on the exterior of the barriers 4. One of the barriers and oneof the pole pieces are omitted on the drawing for greater clearness ofillustration.

A magnetic flux is set up across the pole pieces 5 by a blowout coil 6,in the usual manner, the coil thus being connected in series with thecircuit 7. A pair of relatively movable switch members 8 and 9 areprovided with contact members 10 and 11, respectively, that areconnected in the circuit 7. The contact members'lO and 11 are providedwith are horns 12 and 13, respectively,

the horn 12 being provided with a lower 1922. Serial no. 566,005.

. section 14, and an upper section. 15 that is insulated therefrom, andthe horn 13 being provided with a lower portion 16 and an upper portion17 that is insulated from the lower portion. a 1

An auxiliary blow-out coil 19 is electrically connected to the hornmember 15 and the contact member 10 and an auxiliary blowout coil 20 issimilarly connected to the horn member 17 and the contact member 11.

Upon the separation of the contact members 10 and 11 and the formationof an arc thereacross, such are will move upwardly, partially owing toits natural tendency to rise and partially owing to the influence ofblow-out coil 6. As the arc rises, it will pass from the horn sections14 and 16 to the horn sections 15 and 17. At this point, theeffectiveness of the repulsive force exerted thereupon by the coil 6will be considerably reduced. However, when the arc reaches the hornsections 15 and 17 the auxiliary blowout coils 19 and 20 will beintroduced into the circuit and will set up a magnetic flux tosupplement that of the main coil 6 and thereby cause'an acceleration inthe movement of the are upwardly along the horns. It will sections, suchas 15-15 and 17-17, with v a blowout coil interposed between each of twoadjacent sections, where it is desired to employ a plurality ofauxiliary blowout coils in each horn or when the horns are ofconsiderable length.

-In setting forth a preferred embodiment of my invention, I do not limitmyself to the employment of magnetic blowout devices, but contemplatealso the employment of other forms of auxiliary blowout devices that mayeither accelerate the movement of an arc or set up additional blowoutforces when such are approaches the limit of effectiveness of a mainblowout device.

I claim as my invention: 7

1 The combination with a pair of relatively movable electricalconductors, of a pair of arc horns, each of which is composed of twosections that are insulated from each other, of blowout means adjacentto the point auxiliary magnetic blowout coils in series with the uppersections of the said horns.

2. The combination with a .air of arc horns each of which is compose oftwo sections that are insulated from each other, of blow-out means forinitiating the movement of an arc therealong and an auxiliary blowoutcoil connected in series. with the outermost section, means forintroducing an auxiliary blow-out force at a point intermediate the endsof the horns.

3. The combination with a pair of relatively movable contact members, ofan arc horn for each of. said members, each of which arc horns iscomposed of sections insulated from each other and with an auxiliaryblow-out coil in series with the outer section and with the contactmember, such coil being located at a point intermediate the endsofthe'horn with which it is associated.

4. The combination with a pair of rela tively movable contact members ofarc horns therefor each of which is composed of two sections that areinsulated from one another, a blowout device associated with one of thehorns, and means for including the blow-out coil in the circuit of thearc stream when the said stream contacts with an outermost section of anarc horn. i

5.The combination with a pair of relatively movable contact members, ofa main blow-out coil, a pair of arcing horns one of which is composed ofa plurality of sections that are insulated from one another, anauxiliary blow-out coil associated with one of said horns, and means forintroducing the auxiliary coil into the circuit when an arc that hasbeen formed across the contact members contacts with an outer section ofthe sectional are horn.

v In testimony whereof, I have hereunto subscribed my name this 22nd dayof May, 1922.

HOWABD H. JOHNSTON.

